U.S. patent number 10,905,287 [Application Number 15/746,190] was granted by the patent office on 2021-02-02 for appliance for foaming beverage or foodstuff.
This patent grant is currently assigned to Societe des Produits Nestle S.A.. The grantee listed for this patent is NESTEC S.A.. Invention is credited to Alexa Perrin, Luan Vu Tran, Xuan Mai Tu.
United States Patent |
10,905,287 |
Tu , et al. |
February 2, 2021 |
Appliance for foaming beverage or foodstuff
Abstract
An appliance to foam a liquid for consumption, the appliance
comprising: a container mounting portion to mount thereto a
container to contain said liquid; an agitation system configured to
foam said liquid, said system comprising a stator arranged external
a mounted container, said stator configured to generate a rotating
magnetic field for transmission of torque to rotate a rotary
agitator arranged in a mounted container, wherein said stator
comprises at a circuit board with electrically conductive portions
formed thereon.
Inventors: |
Tu; Xuan Mai (Ecublens,
CH), Tran; Luan Vu (Vufflens-la-Ville, CH),
Perrin; Alexa (Savigny, CH) |
Applicant: |
Name |
City |
State |
Country |
Type |
NESTEC S.A. |
Vevey |
N/A |
CH |
|
|
Assignee: |
Societe des Produits Nestle
S.A. (Vevey, CH)
|
Family
ID: |
1000005333320 |
Appl.
No.: |
15/746,190 |
Filed: |
July 8, 2016 |
PCT
Filed: |
July 08, 2016 |
PCT No.: |
PCT/EP2016/066268 |
371(c)(1),(2),(4) Date: |
January 19, 2018 |
PCT
Pub. No.: |
WO2017/016847 |
PCT
Pub. Date: |
February 02, 2017 |
Prior Publication Data
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|
|
Document
Identifier |
Publication Date |
|
US 20180206678 A1 |
Jul 26, 2018 |
|
Foreign Application Priority Data
|
|
|
|
|
Jul 24, 2015 [EP] |
|
|
15178192 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01F
13/0854 (20130101); B01F 3/04453 (20130101); A47J
43/085 (20130101); A47J 43/0465 (20130101); A47J
31/4496 (20130101); B01F 2215/0014 (20130101); B01F
2215/0022 (20130101) |
Current International
Class: |
A47J
43/08 (20060101); A47J 43/046 (20060101); A47J
31/44 (20060101); B01F 3/04 (20060101); B01F
13/08 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1736013 |
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Feb 2006 |
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CN |
|
101312308 |
|
Nov 2008 |
|
CN |
|
102148544 |
|
Aug 2011 |
|
CN |
|
103348569 |
|
Oct 2013 |
|
CN |
|
104567651 |
|
Apr 2015 |
|
CN |
|
104604100 |
|
May 2015 |
|
CN |
|
H08223831 |
|
Aug 1996 |
|
JP |
|
2014009858 |
|
Jan 2014 |
|
WO |
|
Other References
Chinese Office Action for Appl. No. 2016800409453 dated Jul. 3,
2020. cited by applicant.
|
Primary Examiner: Yoo; Hong T
Attorney, Agent or Firm: K&L Gates LLP
Claims
The invention claimed is:
1. A method of foaming a liquid for consumption using an appliance
comprising a container mounting portion to mount thereto a
container to contain the liquid; an agitation system configured to
foam the liquid, the system comprising a stator arranged external a
mounted container, the stator configured to generate a rotating
magnetic field for transmission of torque to rotate a rotary
agitator arranged in the mounted container; and the stator
comprising at a circuit board with electrically conductive portions
formed thereon, wherein the electrically conductive portions are
connected with at least a two phase configuration, each phase being
arranged such that a face of the circuit board comprising a phase
comprises a single phase only, the method comprising: generating
the rotating magnetic field by applying electrical energy to the
electrically conductive portions of the stator formed on the
circuit board; and rotating the rotary agitator arranged in the
container for containing the liquid by applying the torque from
said field to the rotary agitator.
2. The method according to claim 1, wherein the electrically
conductive portions are arranged into active portions that each
generate a magnetic pole for the rotating magnetic field.
3. The method according to claim 1, wherein the stator comprises an
additional circuit board arranged as a laminate with the circuit
board.
4. The method according to claim 1, wherein the electrically
conductive portions of each phase are complimentary in shape to
each other and are rotationally offset to each other.
5. The method according to claim 1, wherein the stator extends over
a portion of a base of the container.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a National Stage of International
Application No. PCT/EP2016/066268, filed on Jul. 8, 2016, which
claims priority to European Patent Application No. 15178192.9,
filed on Jul. 24, 2015, the entire contents of which are being
incorporated herein by reference.
TECHNICAL FIELD
The present invention relates to an appliance for the foaming of a
beverage or foodstuff, the appliance comprising an agitator and a
magnetic drive system for driving said agitator.
BACKGROUND
It is desirable to foam (i.e. to aerate to a froth by the trapping
of air pockets) beverages or foodstuffs, or components thereof,
during beverage preparation. One example is milk that is foamed
with coffee added thereto to form a latte or a cappuccino. A
further example is the whisking of egg whites or cream to a
mousse.
Accordingly various appliances exist to automate a foaming process.
An example of one such appliance is disclosed in WO 2006/050900,
wherein a container for containing a liquid to be foamed has
arranged therein a rotary agitator which is rotated for said
foaming. In particular, the rotary agitator is part of an agitation
system that further comprises: permanent agitator magnets
incorporated on the rotary agitator; permanent drive magnets
arranged external the container; a rotor operable to rotate said
drive magnets, whereby rotation of the drive magnets effects a
rotating magnetic field to transmit torque to the agitator mag
nets.
In particular the rotor is driven by an electrically operated
motor, which is arranged beneath the container. A drawback with
such an arrangement is that the housing of the appliance has to
house said motor and the drive magnets, both of which are bulky and
impose size constraints on the housing, which is undesirable for
reasons material wastage and economy of space on a worktop. A
further drawback is that said drive magnets are limited in the
amount of torque they can apply to the whisk by virtue of their
degree of magnetisation.
SUMMARY OF THE INVENTION
An object of the invention is to provide an appliance with an
agitation system which is more compact.
It would be advantageous to provide an agitation that is cost
effective to manufacture and/or assemble.
It would be advantageous to provide an agitation capable of
applying high torque to a rotary agitator.
Objects of the invention are achieved by: the appliance according
to claim 1 and the method according to claim 15.
Disclosed herein according to a first aspect of the invention is an
appliance (e.g. for home use by an end user) to foam (e.g. to
aerate or froth) a liquid for end user consumption, the appliance
comprising: a container mounting portion to mount thereto (e.g.
removably or permanently mounted) a container to contain said
liquid; an agitation system configured to foam said liquid, said
system comprising a stator arranged external a mounted container
(e.g. beneath a base of a mounted container), said stator
configured to generate a rotating magnetic field for transmission
of torque to rotate a rotary agitator arranged in a mounted
container, wherein said stator comprises at a circuit board with
electrically conductive portions formed thereon. The rotary
agitator and stator thus form an electric motor. The rotating
magnetic field thus extends into a mounted container and rotates
therein.
Accordingly the object of the invention is achieved since the
stator of the appliance is particularly compact in comparison to
the prior art, which comprises arranged within the appliance a
motor driving permanent magnets. Moreover, a stator formed with
electrically conductive portions on a circuit board can be
conveniently and precisely formed when compared to a coiled wire
arrangement. Furthermore it has enhanced heat dissipation.
The stator may be generally disc shaped. The stator may be arranged
generally perpendicular to the axis of rotation of said field. The
stator preferably extends parallel to a base of a mounted
container. Advantageously the arrangement is compact. The circuit
board(s) comprise a non-conductive material, such as polyethylene
terephthalate (PET) or glass fibre reinforced (fiberglass) epoxy
resin. The electrically conductive material generally comprises a
metal, such as copper. The electrically conductive material can be
formed on the circuit board(s) by known means, e.g. etching or
printing. Advantageously the electrically conductive portions are
formed conveniently with a high level of precision.
The stator may comprise one or a plurality (e.g. and number between
1 and 20, such as 2, 3, 4, 6) of said circuit board, whereby the
plurality of said boards are arranged in the form of a stack (e.g.
layered in a generally of fully overlapping arrangement),
preferably with the centres thereof aligned to the axis of rotation
of the field. The plurality of circuit boards are fixed together,
e.g. bonded, to form a laminate. Advantageously the plurality of
boards enables a high current density in the stator and thus a high
magnetic field strength for transmission of high torque. The stator
may comprise a circuit board with electrically conductive portions
formed on one or both faces of the circuit board. Advantageously
forming the electrically conductive portions on both faces of a
circuit board enables a high current density in the stator and thus
a high magnetic field strength for transmission of high torque. In
the example wherein there is a plurality of circuit boards with
adjacent faces thereof comprising electrically conductive portions
an electrical insulator, e.g. an isolant such as a glass fibre,
epoxy resin, is preferably arranged between the circuit boards.
The electrically conductive portions may be connected with a
multiphase configuration, e.g. 2, 3, 4, 5, 6 or other suitable
number of phases. Preferably a 3 phase configuration us utilised. A
phase herein is defined conventionally with respect to electrically
operated motors, e.g. each phase comprises an independent
arrangement of electrically conductive portions arranged to
generate a static magnetic field at a particular position when a
current travels therethrough. A rotating magnetic field is achieved
by sequentially switching the current through the phases, e.g. a
phase is switched on by the application of current with a square
wave or other suitable waveform. The electrically conductive
portions of each phase may be arranged to be multipolar, e.g. with
2, 3, 4, 5 or other suitable number of pole pairs. Advantageously,
having multiple pole pairs enables smooth torque delivery, and in
particular a complex arrangement of many poles can be conveniently
and precisely formed on the circuit boards using one of the
aforesaid methods. The said multiphase, multipolar configuration is
preferably configured to generate a rotating magnetic field to
transmit torque to a corresponding multipolar permanent magnet
arrangement of the rotary agitator arranged in the container.
The electrically conductive portions of each phase may be
complimentary in shape (e.g. active portions thereof have a
substantially similar shape) to each other and may be rotationally
offset to each other, e.g. a 3 phase, 8 pole (i.e. 4 pole pairs)
configuration, wherein each phase is rotationally offset by 30
degrees. Advantageously each phase can be conveniently formed using
the same process (e.g. template) and then rotationally offset
during assembly to define the separate phases.
Each phase may be arranged such that a face of the circuit board(s)
comprising a phase comprises a single phase only, e.g.: each phase
is arranged on one face only and not on any other faces; or each
phase is distributed over a plurality of faces with each of said
plurality of faces only comprising one phase only. Advantageously a
phase can be layered over several faces (e.g. 2, 3, 4, or more) to
achieve a high current density in the stator and thus a high
magnetic field strength for transmission of high torque.
With an arrangement with the phases disposed over several faces of
the circuit board(s), the phases (e.g. each of the faces of a
phase) may be symmetrically disposed about a central plane, the
central plane being arranged centrally in a through-thickness
direction of the circuit board(s), e.g.: a 2 phase arrangement
wherein there are two boards, phase 1 is arranged on the outer
faces thereof and phase 2 is arranged on the inner faces thereof; a
3 phase arrangement wherein there are three boards, phase 1 is
arranged on the outer faces thereof, phase 2 is arranged on the
inner faces of the outer boards, and phase 3 is arranged on the
faces of the central board. The said symmetrical arrangement may
also be extended to configurations wherein more than one phase is
arranged on a face, e.g.: a phase arrangement wherein there is a
single board and phase 1 and phase 2 are evenly distributed across
both faces (it will be appreciated that such an arrangement is
achievable by having on each face alternating active portions of
each phase, which may be serially connected between the board). In
the instance of there being more than one board, the central plane
is arranged at the centre of the laminate.
Advantageously, with the aforedescribed symmetric arrangement of
the phases the magnetic field strength at the rotary agitator is
substantially the same for each phase, which result in a more
uniform transfer of torque to the rotary agitator together with
increased efficiency. With such an arrangement it is preferable for
reasons of complexity that a face comprises one phase only, however
as previously discussed the said symmetric arrangement of the
phases is also possible when a face comprises more than one
phase.
The electrically conductive portions are preferably arranged into
active portions, whereby each active portion is configured to
generate a pole for said torque transmission. An active portion can
be defined as a generating a north pole or a south pole of a pole
pair for torque transmission. Generally the active portions are
circumferentially and equidistantly disposed on a face of a circuit
board about the axis of rotation of the magnetic field. Generally
each active portion comprises one of two predetermined
arrangements.
The electrically conductive portions may comprise vias for
connection (e.g. for interconnection of phases disposed over
several faces and/or for transmission of current to and from the
stator) arranged distal the active portions (i.e. they are not
arranged within an active portion). In particular the vias can be
proximal a periphery of the circuit boards and/or proximal a centre
of the circuit boards. Generally the vias may be the through
extending type. Advantageously the efficiency of the active
portions is enhanced since the vias do not interfere with their
positioning/arrangement, and thus magnetic field generation.
For phases that are distributed over several layers, the active
portions that comprise a phase that are arranged on different faces
are preferably configured such that superposed active portions
generate a magnetic field vector in the same direction. The said
direction may alternate between adjacent superposed active portions
to define a plurality of poles. In particular, the different faces
comprising a phase each have substantially the same shape of active
portion and are rotationally offset by an amount corresponding to
(or substantially) an active portion, e.g. a 3 phase, 8 pole (i.e.
4 pole pairs) configuration, wherein each face is rotationally
offset by 45 degrees. Advantageously, a phase can be conveniently
formed using the same template of the active portions, each face is
then rotationally offset by an active potion in the board laminate.
The active portions may be arranged with either a first or second
shape. Superposed active portions may comprise active portions of
the first and second shape. On a face the adjacent active potions
may alternate between the first and second shape.
The active portions may comprise a plurality of tracks. An active
portion may comprise two generally radially (e.g. exactly radial or
radial .+-.10 or 5 degrees) extending portions which are
interconnected (e.g. by interconnecting portions which may be
generally circumferentially arranged). Adjacent active portions
preferably share the same radially extending portion. The phases
may be arranged between faces such that the radially extending
portions are generally aligned and overlapping, and which are
preferably connected with the current traveling there through in
the same direction. Advantageously a high current density is
achieved. The active portions on a face may comprise
interconnections of the radial portions alternating between
proximal a periphery and a centre of the circuit board, i.e. to
form a first and second shape, which is generally a C shape.
Superposed active portions may comprise radially extending portions
that are interconnected on a face proximal a periphery of the
board, and complimentary radially extending portions that are
interconnected on another face proximal a centre of the board.
The optionally tracks of the active portions may be 0.25-2 mm in
thickness (i.e. in the planar direction of the stator). The
optionally tracks of the active portions may be narrower in
thickness and more densely packed along the radially extending
portions rather than the interconnecting portions, e.g. they are
less than 50% or 75% of the thickness at the interconnection
portions. Advantageously, the increased width of the
interconnecting portions enables improved heat dissipation.
The stator may extend over a substantial portion of a base of a
mounted container, e.g. an overlap of at least 90% or all of the
area of the base of a mounted container. Advantageously, the
magnetic field is generated over a large surface area and can thus
induce a large amount of torque in the rotary agitator. The stator
preferable extends parallel to a base of a mounted container. The
stator is preferably arranged adjacent a base of the container,
e.g. a mounted container sits is at least partially supported by
the stator, and sits on the stator with an optional insulating
material therebetween.
The container mounting portion may be configured for permanent or
removable attachment of the container, e.g. a bonded, force fit, or
screw fit. Advantageously a container which is removable can be
removed for cleaning. An exterior surface of the stator proximal
the container may comprise a protective coating for mounting the
container thereon. Advantageously, the appliance is compact.
The appliance may comprise a container to contain said liquid for
mounting to said mounting portion (e.g. it may be mounted to the
mounting portion). The appliance may comprise a rotary agitator for
arrangement in said container (e.g. it may be arranged in said
container), wherein the rotary agitator comprises one or more
agitator magnets defining magnetic poles for transmission of torque
from the magnetic field generated by the stator to the rotary
agitator (e.g. the other components of the rotary agitator).
The container may comprise at a base thereof a location member for
location of the rotary agitator. The location member is preferably
located such that when the container is mounted it is at a centre
of rotation of the magnetic field.
The rotary agitator may comprise an array of magnetic poles
circumferentially disposed about an axis of rotation. The poles may
be formed of discrete magnets, e.g. magnets that comprises single
pole pairs, or magnets that comprise a plurality of pole pairs.
Disclosed herein according to a second aspect of the invention is a
method of foaming a liquid for consumption using the appliance
according to any feature of the first aspect, said method
comprising: generating a rotating magnetic field by applying
electrical energy to electrically conductive portions of a stator
formed on a circuit board; rotating a rotary agitator arranged in a
container for container liquid by applying a torque from said field
to the rotary agitator. The method may comprise filling the
container with liquid to be foamed. Generating a rotating magnetic
field may comprise sequentially switching the electrical current
between the phases of the stator, e.g. by means of a processor.
Disclosed herein according to a third aspect of the invention is a
stator for an electrically rotating machine. The stator for the
aforesaid electrical rotating machine may comprise any feature
according to the first aspect of the invention. The electrical
rotating machine may comprise a motor, such as a pancake or axial
rotor motor. The electrical rotating machine may comprise an
electrical generator. The electrical rotating machine may comprise
the appliance according to the first or second aspect.
Disclosed herein according to a fourth aspect is an electrical
rotating machine comprising the stator according to the third
aspect. The electrical rotating machine may comprise a motor, such
as a pancake or axial rotor motor. The electrical rotating machine
may comprise an electrical generator. The electrical rotating
machine may comprise the appliance according to the first or second
aspect.
The above aspects of the invention may be combined in any suitable
combination. Moreover, various features herein may be combined with
one or more of the above aspects to provide combinations other than
those specifically illustrated and described. Further objects and
advantageous features of the invention will be apparent from the
claims, from the detailed description, and annexed drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention, and to show how
embodiments of the same may be carried into effect, reference will
now be made, by way of example, to the accompanying drawings in
which:
FIG. 1 is an illustrative sectional view of an embodiment of an
appliance to foam a liquid for end user consumption;
FIG. 2 is block diagram of a control system for the appliance of
FIG. 1;
FIGS. 3a-3c show various views of an embodiment stator of an
agitation system of the appliance of FIG. 1;
FIGS. 4a-4e show plan views of embodiment arrangements for
electrically conductive portions of the stator of FIG. 3, in
particular the arrangements may in one example be taken as being to
scale, i.e. 1.1.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
Appliance for Foaming
An appliance for foaming 2, an example of which is illustrated in
FIG. 1, comprises at a first level thereof: a base unit 4 to
transmit torque to a rotary agitator; a container 6 to contain
liquid for end user consumption; a rotary agitator 8 to foam said
liquid, which are described sequentially as follows.
Base Unit
The base unit 4 transmits torque to the rotary agitator 8 by means
of a magnetic field, and comprises at a first level thereof: a
housing 10; container mounting portion 12; agitation system 14;
optionally a heater 16; control system 18, which are sequentially
described as follows.
Housing
The housing 10 houses and supports said first level components and
comprises: a base 22 for abutment of a horizontally arranged
support surface; a body 20 for mounting thereto the other first
level components.
Container Mounting Portion
The container mounting portion 12 is operable to mount the
container 6 to the base unit 4. The container mounting portion 12
may be configured for permanent mounting of a container, e.g. it
comprises a surface for locating the container to which the
container can be bonded. Preferably the container mounting portion
12 is configured for removable attachment to the container, e.g. it
comprises a force fit or screw fit. An advantage of a removable
attachment is that the container 6 can be detached from the base
unit 4 for cleaning. The mounting portion 12 may comprise the
stator with an optional a protective coating (e.g. an insulating
lacquer or a glass fibre epoxy resin) on an outer surface thereof
for mounting the container 6 thereon.
Agitation System
The agitation system 14 is operable to foam liquid in the container
6 by mechanical agitation, in particular by transmission of torque
via a magnetic field to a rotary agitator 8, and comprises: a
stator 24; a rotary agitator 8; an optional core 30.
The stator 24 is operable to receive phased electrical energy and
to generate therefrom a rotating magnetic field. The stator 24
comprises at least one circuit board with electrically conductive
portions formed thereon and is discussed in more detail later
on.
The rotary agitator 8 comprises an array of magnetic poles that are
circumferentially disposed about an axis of rotation for
interaction with the rotating magnetic field generated by the
stator 24. Agitator magnets 26 of the rotary agitator 8 form said
poles and comprise a magnetically hard material capable of a
persistent magnetic field. The magnets 8 are configured the
transmission of torque derived from their interaction with the
rotating magnetic field to the remainder of the rotary agitator 8.
The magnets 26 may comprise discrete units with each comprising a
north and south pole. Alternatively one or more of the units may be
integrated, e.g. in an annular ring. Other components of the rotary
agitator 8 are discussed in more detail later on.
The optional core 30 is for enhancing the rotating magnetic field
and typically comprises a ferromagnetic metal such as iron. The
code 30 is in general an axially arranged toroid or annular ring
positioned proximal a face of the stator 24 that is distal the
container 6.
Heater
The optional heater is operable to 16 heat the liquid in the
container 6. Preferably the heater 16 comprises an induction coil
operable to heat by electromagnetic induction the rotary agitator
8. Alternatively it may heat the container 6, e.g. the heater
comprises a resistive element for heating by conduction.
Control System
The control system 18, an example of which is illustrated in FIG.
2, is operable to control the agitation system 14 and optional
heater, and generally comprises: a user interface 32; optional
sensors 34; processor 36; power supply 38, which are described
sequentially.
The user interface 32 comprises hardware to enable an end user to
interface with the processor 36 and hence is operatively connected
thereto. More particularly: the user interface receives commands
from a user; a user interface signal transfers the said commands to
the processor 36 as an input. The commands may, for example, be an
instruction to execute a foaming process and/or a heating process.
The hardware of the user interface 32 may comprise any suitable
device(s), for example, the hardware comprises one or more of the
following: buttons, such as a joystick button or press button;
joystick; LEDs; graphic or character LDCs; graphical screen with
touch sensing and/or screen edge buttons.
Optional sensors 34 are operatively connected to the processor 36
to provide an input for monitoring said process. The sensors 40
typically comprise one or more of the following: liquid temperature
sensors; liquid level sensors; position sensors (e.g. hall sensors)
for sensing a position of the magnets of the rotary agitator 8 with
respect to the stator as will be discussed.
The processor 36 is generally operable to: receive an input, i.e.
the commands from the user interface 32 and/or from the sensors 34;
process the input according to program code stored on a memory unit
(or programmed logic); provide an output, which is generally the
said foaming process and/or a heating process. The process may be
executed with open-loop control, or more preferably with
closed-loop control using the input signal from the sensors 34 as
feedback. The processor 36 generally comprises memory, input and
output system components, which are arranged as an integrated
circuit, typically as a microprocessor or a microcontroller. The
processor 36 may comprise other suitable integrated circuits, such
as: an ASIC; a programmable logic device such as an FPGA; an
analogue integrated circuit such as a controller. The processor 36
may also comprise one or more of the aforementioned integrated
circuits, i.e. multiple processors. An example of a suitable
component of a processor for stator control is the ESCON 36/3 motor
controller by Maxon, which may be controlled by a further
processor.
The processor 36 generally comprises a memory unit for storage of
the program code and optionally data. The memory unit typically
comprises: a non-volatile memory e.g. EPROM, EEPROM or Flash for
program code and operating parameter storage; volatile memory (RAM)
for data storage. The memory unit may comprise separate and/or
integrated (e.g. on a die of the processor) memory.
The power supply 38 is operable to supply electrical energy to the
processor 36, agitation system 14 and heater 16. The power supply
38 may comprise various means, such as a battery or a unit to
receive and condition a mains electrical supply.
Container
The container 6, and example of which is illustrated in FIG. 1, is
operable to contain the liquid for foaming. Typically the container
has a capacity of 0.2-0.5 litres. The container 6 may be
cylindrical (6). The container is generally formed of a material
that is suitably transparent to a magnetic field, e.g. glass.
The liquid to be foamed in the container is generally any potable
liquid including foodstuffs. Typically it is milk or comprises
milk.
Rotary Agitator
The rotary agitator 8, an example of which is illustrated in FIG.
1, is operable to rotate to agitate the liquid in the container 6
to effect its foaming. The rotary agitator 8 comprises: an axially
extending body 40; a support portion 42, radially extending from
said body 40 for supporting the agitation portion 28 and the
agitator magnets 26. The agitation portion 28 may be contoured (as
illustrated) or otherwise formed (e.g. comprising holes) to effect
fluid agitation upon rotation. The body 40 comprises at an end
thereof a location member configured to engage with a complimentary
location portion of the container 6, e.g. an extension on one of
the body 40 or container 6 for insertion into a cavity on the other
of the body 40 or container 6.
The arrangement and pole configuration of the agitator magnets 26
of the rotary agitator 8 is complementary to the poles of the
stator 24, e.g. for the later discussed example stator
configuration shown in FIGS. 3 and 4, wherein the stator comprises
8 poles, i.e. 4 pole pairs, there are the same number of poles in
the rotary agitator, which are arranged at a complimentary radial
distance from the centre of rotation of the magnetic field.
Stator
The stator 24, an idealisation of which is shown in FIG. 3,
comprises a circuit board 44 and electrically conductive portions
46 arranged thereon. The stator 24 may be arranged proximal a base
of the container 6 such that it is in operative proximity to the
rotary agitator 8, and example of such an arrangement is shown in
FIG. 1. In particular, it may fully or at least partially overlap
(e.g. by covering at least 80% or 90% of the surface area of the
base) said base of the container 6. Typically the stator 24 is disc
shaped with the axis of rotation of the associated magnetic field
arranged at a centre thereof, however it will be appreciated that
it may comprise other shapes. The diameter of the stator (when in
disc form) may be 5 cm-15 cm. The thickness of an individual
circuit board is selected for suitable thermal conduction, e.g.
1-2, such as 1.6 mm.+-.0.15 mm.
The electrically conductive portions 46 and circuit board(s) 44 may
have various configurations as will be discussed. They are arranged
to effect a multipolar (e.g. 2, 3, 4, 6 or more pole pairs),
multiphase (e.g. 2, 3, 4 or more phase) motor configuration, which
incorporates a rotor comprising the agitator magnets 26 of the
rotary agitator 8. More particularly, the stator and rotor are
configured to effect a brushless DC or AC synchronous motor
configuration. The electrically conductive portions 46 are arranged
to define active portions 48 for generation of the magnetic poles.
The poles are connected in phases, whereby the individual phases
can be switched sequentially to effect rotation of a magnetic
field. In particular and active portion is configured to generate
one pole (i.e. with a magnetic field vector which is in the north
or south direction) of a pole pair.
In a first embodiment stator (not shown) the electrically
conductive portions 46 are arranged on one face of a signal circuit
board 44. As an example, they are arranged with the active portions
thereof extending circumferentially and sequentially in phase
order, e.g. a 3 phase configuration, with phase 1, 2, 3
circumferentially extending.
In a second embodiment stator (not shown) the electrically
conductive portions 46 are arranged on both faces of a single
circuit board 44. As an example, the aforesaid arrangement for a
single face is repeated on both faces of said board 44.
In a preferred third embodiment stator, an example of which is
shown in FIG. 3, the stator comprises a plurality of said circuit
boards, whereby said boards are arranged in the form of a stack,
whereby the electrically conductive portions 46 are formed on one
or both sides of the associated circuit boards 44. It will be
appreciated that adjacent faces of said boards can be electrically
isolated by means of an electrically insulating coating such as a
glass fibre epoxy resin, e.g. prepreg TU-768 or TU-768P by Taiwan
Union Corporation Technology. In the example the stack comprises 3
boards, 44A, 44B, 44C, it will be appreciated that any suitable
number of boards can be utilised, e.g. 4 or 6. In the following,
further exemplary arrangements of the preferred third embodiment
will be discussed.
The electrically conductive portions 46 of different faces are
interconnected by vias 50 thereof, which are preferably arranged
distal said active portions 50 (i.e. a connecting portion of an
electrically conduction portion 46 connects a via 50 with an active
portion 48). More particularly, the vias 50 can be arranged
proximal a periphery of the circuit boards 44 and/or proximal a
centre of the circuit boards 44. The vias 50 are generally of the
through hole type (e.g. extending through one or more circuit
boards), however other suitable arrangements are envisaged, e.g. a
blind, castellated hole type. An example of such an arrangement is
shown in FIG. 4a, whereby via 50A is proximal a periphery and via
50B is proximal a centre of the board 44.
The electrically conductive portions 46 are generally complimentary
in shape, i.e. each face comprises the same arrangement, but to
achieve the different phases the faces are rotationally offset. As
an example of such an arrangement (not shown) two circuit boards
have arranged on three faces different phases, with each phase
having 8 active portions providing 4 pole pairs, and being
rotationally offset from the first phase by 30 degrees.
In the following the third embodiment is described has having only
one phase on a face (however in a more complex example it will be
appreciated that more than one phase could be arranged on a face).
In the last example of the third embodiment, a phase was arranged
on a single face, however in a preferred example of the third
embodiment a phase may be distributed over a plurality of faces,
e.g. 2, 3 or 4 faces. In this way complementary active portions 48
can be layered to increase current density and field strength.
FIGS. 3a and 3b illustrate such a preferred example, wherein there
are three circuit boards 44A, 44B, 44C, with the electrically
conductive portions 46 arranged on each face, i.e. utilising all 6
faces (it will be appreciated that 6 circuit boards may
alternatively be used with a single face of each utilised) to
define 3 phases. In particular: phase 1 is arranged on the outer
faces 52A, 52F of the outer circuit boards 44A, 44C; phase 2 is
arranged on the inner faces 52B, 52E of the outer circuit boards
44A, 44C; phase 3 is arranged on the faces 52C, 52D of the inner
circuit board 44B. In this way each phase is symmetrically disposed
about a central plane, which in this example is centrally though
the inner circuit board 44B. It will be appreciated that the said
symmetric arrangement can be extended to different numbers of
circuit boards 44 and phase arrangements, e.g. a four phase
arrangement arranged with a phase over two faces and four circuit
boards 44 with both faces used. The symmetric arrangement is
advantageous since the strength of the magnetic field at the rotary
agitator 8 is balanced, which would not be the case if for example
a first phase was arranged on the two faces most proximal the
rotary agitator, and a third phase was arranged on the two faces
most distal the rotary agitator 8.
Considering the arrangement of the active portions 48 in more
detail, when a phase is split over several faces the superposed
active portions 48 of the same phase, which are arranged on
different faces, are generally complimentary (i.e. they generate a
pole with a magnetic field vector of the same direction). The other
phases can be arranged in the same manner as per the first phase,
but rotationally offset therefrom. Referring to the example in FIG.
4 to illustrate this arrangement: the two electrically conductive
portion arrangements that comprise phase 1 are shown in FIGS. 4a
and 4b, FIG. 4c shows their supposition; phase 2 comprises the same
arrangement, but rotated through 30 degrees, the supposition of the
two electrically conductive portion arrangements that comprise
phase 2 are shown in FIG. 4d; phase 3 comprises the same
arrangement, but rotated through 60 degrees, the supposition of the
two electrically conductive portion arrangements that comprise
phase 3 are shown in FIG. 4e.
The active portions 48 are configured to generate a magnetic field
vector in a first direction, or are configured to generate a
magnetic field vector in a second direction, whereby said
configurations alternate on a face to define a plurality of poles.
Referring to the example phase shown in FIGS. 4a and 4b: FIG. 4a
comprises 8 active portions, whereby the electrical energy (as
indicated in the figures by the direction of the current I
according to conventional flow notation) is transmitted thereto at
via 50A and therefrom at via 50B, accordingly the field vector at
the active portion 48 most proximal via 50A is out of the page in
the associated region (as indicated), and into the page at the most
proximal active portion 48 in the anticlockwise direction and so on
as indicated; the active portions 48 of FIG. 4b are connected to
those of FIG. 4b by means of the vias 50B and 50C hence the current
is in a different circumferential direction such that the field
vector is in the same direction in the superposed active portions
shown in FIG. 4c. Accordingly, in the example the active portions
48 of the associated faces of a phase are rotationally offset by an
amount corresponding to an active portion and the active portions
between said faces are interconnected such that a current there
through is in an opposed direction such that the magnetic field
vector generated by superposed active portions is in the same
direction.
Generally an active portion 48 comprises two substantially radially
extending portions that are interconnected by interconnecting
portions. The said radially extending portions are typically 1-2 cm
in length and 0.5-1 cm in width. The said radially extending
portions comprise a plurality of tracks to control the current flow
direction, typically there are 5-10 tracks. In particular the
tracks may vary in width, for example, as illustrated in FIG. 4,
the tracks are narrower and more densely packed along the radially
extending portions. Advantageously, the increased width of the
interconnecting portions enables improved heat dissipation.
As shown in FIG. 4a, a radially extending portion is shared between
adjacent active portions 48 on the same face. Moreover, the
radially extending portions are interconnected alternating between
proximal a periphery and a centre of the board, e.g. to form a U
shape, whereby the interconnecting side alternates such that two
adjacent active portions form an S shape. Alternatively put, an
active portion comprises two sectorialy arranged radially extending
portions, which are serially interconnected with neighbouring
active portions. The radially extending portions generally overlap
providing a high current density and thus magnetic field strength,
an example of which is illustrated in FIG. 4c. In particular, to
achieve the same polarity of the magnetic field the direction of
the current through overlapping radially extending portions is this
same. For the superposed active portions distributed on different
faces: the radially extending portions can be interconnected on one
face proximal a periphery of the board, the radially extending
portions can be interconnected on another face proximal a centre of
the board, an example of which is illustrated in FIG. 4c.
The active portions 48 may comprise various other arrangements (not
show and including for the first and second embodiment stator), for
example, they may be arranged in a substantially rectangular shape,
with a via arranged at an interior and outer of said rectangle for
connection.
The processor 36 is configured to control the current applied
through the phases. The angular frequency of the generated magnetic
field may be variable and/or constant, i.e. a phase locked loop,
with a reference frequency. The position of the rotary agitator 8
can be commutated by position sensors such as an: optical encoder;
magnetic encoder (e.g. a resolver, synchro etc.); hall effect
sensor, with the latter being preferable due to cost and size.
The aforedescribed stator may be incorporated in electrically
rotating machines other than the appliance for foaming a liquid
described herein. For example, the electrical rotating machine may
comprise a motor, such as a pancake or axial rotor motor. The
electrical rotating machine may alternatively comprise an
electrical generator.
TABLE-US-00001 LIST OF REFERENCES 2 Appliance 4 Base unit 10
Housing 20 Body 22 Base 12 Container mounting portion 14 Agitation
system 24 Stator 44 Circuit board 52 Face 46 Electrically
conductive portion 48 Active portion 50 Vias 26 agitator magnets 28
agitation portion (of agitator 8) 30 Core 16 Heater 18 Control
system 32 User interface 34 Sensors 36 Processor 38 Power supply 6
Container 8 Rotary Agitator 40 Body 42 Support portion 26 agitator
magnets (of agitation system 14) 28 agitation portion (of agitation
system 14)
* * * * *